Process of concentrating oxid ores of copper.



RUDOLF GAHL, OF MIAMI, ARIZONA.

PROCESS OF CONCENTRATING OXID ORES OF COPPER.

Specification of Letters Patent.

Patented Feb. 27, 1917.

Application filed December 27, 1916. Serial No. 139,148.

To all whom it may concern Be it known that I, RUDoLF GAHL,3. citizen of the United States, residing at Miami, in the county of Gila and State of Arizona, have invented certain new and useful Improvements in Processes of Concentrating Oxid Ores of Copper, of which the following is a specification.

My invention relates to a process for treating copper ores of the mid type to make them amenable to flotation. These socalled oxid ores (cuprite, tenorite, malachite, azurite, etc.) in contradistinction to the sulfid ores are not ordinarily capable of concentration by flotation.

The process consists in agitating the ground ore or pulp to which flotation oil may have already been added, in the presence 'of an acid, such as sulfuric acid, which dissolves the soluble copper constituents of the ore. The agitation may be readily effected by blowing air into the vessel containing the ore pulp. The pulp is then subjected to the action of finely divided iron, obtained in any suitable manner, as in the form of filings, or the line iron resulting from the action of steel balls in b-all mills, or sponge iron formed by the reduction of iron oxids by carbon or oil at a temperature below the melting point of iron.

The result of the addition of the iron to the pulp is to cause the precipitation of cement copper from the acid solution. The iron is then separated from the pulp in any suitable .manner, as by a magnetic separator. The pulp from which the iron has been separated is then treated in a flotation machine which may be of any of the well-known constructions.

The cement copper and copper-sulfide, if any, present in the pulp are separated by the flotation operation and collected in the usual way.

This treatment may be combined with any of the known processes of ore concentration, for instance, the pulp may undergo a preliminary table or other gravity treatment, or a preliminary flotation before the acid treatment above described. The tailings produced may be subjected to either gravity or flotation concentration.

4 Any suitable apparatus may be employed, one form designed for continuous o eratlon being shown in the accompanying rawings in which A is an agitating tank,wh1ch may be divided by partitions 2, into several compartments, into each of which air under pressure is introduced through pipes 3 connected to an air-main 4:.

The ore-pulp and acid are introduced at the head-end of the tank through pipes 5 and 6. The pulp travels in succession through the compartments and is delivered through pipe '7 to a precipitating tank B similar in construction to the agitating tank A and also provided with agitating means.

From the precipitating tank B, the pulp is delivered by pipe 8 and launder 9 to the magnetic separator C, by which the iron which has not been dissolved is removed. Any suitable form of magnetic separator may be used, such as a belt 10 traveling over a magnetized pulley 11. The iron which is separated is delivered by hopper 12 into a receptacle 13, from which it may be conducted by any suitable elevator 14 to the head end of the tank B, for re-use. The unmagnetic portion of the pulp, passes over plate 15 to a flotation machine D, which may be of any of the well known constructions, such as the heater or pneumatic types. The function of the magnetic separator is not only to economize in iron consumption, but mainly to keep up an appreciable return of iron to the tank B, for the purpose of maintaining in the same, a high percentage of iron particles, although the quantity of iron added in the form of fresh iron may be small. A large surface of metallic iron will thus be constantly exposed to the cop er solutions in the precipitating tank and the reaction will, accordingly take place rapidly. In this manner an agitating tank of very small dimensions serves the purpose of precipitating the copper contained in a large amount of pulp. The flotation machine D roduce's a concentrate consisting mainly of cementcopper, in case there are being treated ores, such as what are known as oxid ores, the copper contents of which are essentiall soluble in sulfuric acid. If, however, sul ds are present in the ore, they will go into the concentrate along with thecement copper.

I claim 1- 1. The process of concentrating oxid ores of copper which consists in adding thereto acid to dissolve the soluble copper 1ngre dients, precipitating the copper from solution by iron, separating the undissolved iron from the pulp, and subjecting the residue to a flotation operation.

2. The process of concentrating oxid ores of copper which consists in adding thereto acid to dissolve the soluble copper ingredients, precipitating the copper from solution by iron, magnetically separating the undissolved iron'from the pulp, and subjecting the residue to a flotation operation.

3. The process of concentrating oXid ores of copper which consists in adding thereto acid to dissolve the soluble copper ingredients, precipitating the copper from solution by iron, separating the undissolved iron from the pulp re-using the recovered iron for further precipitation, and subjecting the residue to a flotation operation.

4. The continuous process of concentrating oxid ores of copper which consists in agitating the pulp in the presence of acid, precipitating the copper from the pulp by metallic iron, magnetically separating the undissolved iron, re-using the thus recovered metallic iron for further precipitation, and subjecting the pulp'containing the cement-copper to flotation.

In testimony whereof I aflix my s1gnature in presence of two Witnesses.

RUDOLF GAHlL.

Witnesses:

F. S. TRELOAR, A. Rim). 

